This document specifies the Internet standards track protocol for four intertwined algorithms in TCP: slow start, congestion avoidance, fast retransmit, and fast recovery. These algorithms are crucial for managing network congestion and improving TCP performance. The slow start algorithm initializes the congestion window to one segment and gradually increases it based on acknowledgments. Congestion avoidance reduces the transmission rate when packet loss is detected and reverts to slow start after a period. Fast retransmit allows TCP to retransmit lost segments immediately upon receiving three consecutive duplicate ACKs, without waiting for the retransmission timer. Fast recovery then performs congestion avoidance to restore the connection to a higher throughput. The document also acknowledges the contributions of Van Jacobson and references several sources for further details.This document specifies the Internet standards track protocol for four intertwined algorithms in TCP: slow start, congestion avoidance, fast retransmit, and fast recovery. These algorithms are crucial for managing network congestion and improving TCP performance. The slow start algorithm initializes the congestion window to one segment and gradually increases it based on acknowledgments. Congestion avoidance reduces the transmission rate when packet loss is detected and reverts to slow start after a period. Fast retransmit allows TCP to retransmit lost segments immediately upon receiving three consecutive duplicate ACKs, without waiting for the retransmission timer. Fast recovery then performs congestion avoidance to restore the connection to a higher throughput. The document also acknowledges the contributions of Van Jacobson and references several sources for further details.